Data processing devices are used to process data and to control, organize and analyze input and output signals. During operation of a data processing device, which usually comprises a processor and a memory, interrupts, so called, will occur. These are signals which indicate an event to the processor. An example of such events may be conditions, results or events generated both within the processor or the CPU (Central Processing Unit) and outside of the CPU, and which require execution of a specific routine in reaction to the event. The specific routine is the interrupt routine, whose start address is located at a given memory address of the memory as an interrupt vector, so called. In addition, interrupt handlers, so called, are in use; they are small program segments which are executed upon occurrence of an interrupt in order, for example, to determine the source of the interrupt.
Since interrupt vectors have to be available as well during cold start or warm start of a data processing device, they are saved in a non-temporary memory sector, such as a ROM (Read Only Memory). However, a ROM has the disadvantage of requiring a very long access time, a fact which entails significant interrupt latencies. For this reason, the suggestion is made, for example, in “ARM Training Material: Technical Training Course 1999, Chapter 16 and Chapter 19” to copy the interrupt vectors into a faster RAM (Random Access Memory) sector after starting the data processing device, and then to overlay this sector over the address sector originally occupied by the ROM. It is also mentioned in connection with this process that the RAM sector is mapped on the place of the original ROM sector. This process makes it possible to cut the interrupt latency approximately in half.